CITY ALIGHTS: California’s City National Bank will serve clients from its 45,000 square feet at 400 Park Ave., a former Syms store. Photo:

A new kind of educated consumer will soon be coming to the former Park Avenue home of Syms — institutional and high-net worth clients of City National Bank.

The Los Angeles-based institution has signed a 15-year lease for a total 45,000 square feet of office and retail space at Waterman Interests’ 400 Park Ave., including a 15,000 square-foot renewal.

The highlight of the deal is a 5,400 square-foot retail banking center on the East 54th Street corner.

The lease also includes 15,000 square feet on the second floor, where landlord principal Philip (Tod) Waterman III expects the tenant to open a “dramatic two-story entrance.” The deal also includes concourse space and a renewal of CNB’s office space on the seventh floor.

We reported last year that Waterman planned to re-brand the former seven-story Syms space as a home to financial-services firms. He said the CNB lease leaves only floors 3-5 available in the former store space. Some 60,000 square feet are still on the market at the 270,000 square-foot address.

Waterman recently completed capital improvements including new elevators, corridors, security features and — most visible to passers-by — new windows that replaced opaque panels during the Syms era. Old signs for the former store will come down in about a week.

CNB’s arrival “should define this corner and building for a very long time,” Waterman said. “It’s exactly the kind of franchise we think is indicative of the value of the property and the neighborhood.”

Terms were not disclosed. Asking rents in the building run $75-95 per square foot, according to brokerage sources.

It isn’t sexy, but it sure is big: the city’s Law Department has signed a monster early lease renewal at SL Green’s 100 Church St. — for 372,520 square feet for 20 years, starting in November 2013.

Asking rents at 100 Church St. are $38 per square foot.

SLG Executive Vice-President Steven Durels said the tower’s slightly more than 1 million square feet are 82 percent occupied. SLG took it over from the Sapir Organization in 2010, when it was barely 60 percent full.

Meanwhile, SLG just refinanced the property with a $230 million, 10-year fixed-rate loan. “The building is now completely stabilized,” Durels said.

Acknowledging that a city agency renewal wasn’t the most glamorous in SLG’s portfolio, Durels noted, “But this is where the activity is downtown — a mid-price point for 50,000 square-foot floors. There’s a lot of activity in that part of the market.”

Before SLG took control of 100 Church, it was considered jinxed over the previous collapse of several high-profile leases. It was also the butt of jokes for its lobby, which Alex Sapir decorated with 22 Swarovski chandeliers.

SLG normalized the lobby, upgraded systems and lured new tenants.

CBRE’s Michael Geoghegan and John Morrill repped the Law Dept.

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In reporting last Friday that the US General Services Administration was close to a lease for nearly 300,000 square feet at 1 World Trade Center — by sending lease terms to Congress for approval — we noted the average cost for the first five years of a 20-year lease was $66.33 per “rentable” square foot as measured by Real Estate Board of New York guidelines.

But we also said the lease will cost the GSA much less than that thanks to subsidies. The effective annual starting rent has been reported as low as $40 per square foot and as high as in the low $50s, although never to our knowledge been confirmed. By comparison, 1 WTC’s glamour tenant, Condé Nast, is to pay in the $60s per square foot to start — a figure itself below-market.

But what subsidies will the GSA enjoy, you ask?

Since we love everything about 1 WTC — including that the GSA lease pushes it over the 50 percent-leased milestone — we pored over GSA Prospectus No. PNY-03-NY13. It says the “levelized annual [lease] cost” is $16.482 million, based on present value of future rent payments amortized as a series equal payments over the term.

But it will be mitigated by a tenant allowance of $77.50 per square foot plus a “supplemental tenant improvement allowance” of $21.583 million.

It isn’t possible to say exactly how much the GSA will pay for the full term because future rents are subject to adjustments. (The “maximum proposed” rent for years 16-20 is $81.91 per square foot.)

It’s also impossible to say because 1 WTC’s owners, the Port Authority and the Durst Organization, declined to comment.